The Ninth and Jefferson Building (NJB) is located on the Harborview Medical Center campus. UW Medicine operates Harborview on behalf of King County.

NJB represents phase two of a multi-phase campus expansion that includes the Norm Maleng Building and north-wing seismic upgrade projects. The goals of this expansion were to remedy significant seismic deficiencies on the campus and address the need for expanded patient capacity. The construction program wasfunded through a combination of voter-approved bonds, Harborview reserves, and special building development financing.

The NJB project was revised from its original plan to include a 14-story medical office tower that spans a full city block. It houses a center of emphasis in infectious disease control including HIV/AIDS and STDs. In addition, specialized services such as the King County Medical Examiner, laboratories, and the Involuntary Treatment Act (ITA) Courtroom are included. Five floors of underground parking, a new computer data center, and retail spaces at street level are among the amenities. The high-rise tower provides leased space for relocating off-campus services and expansion space for additional Harborview Centers of Excellence and compatible community programs.